If it's a bolt-on it's an SB-600. Do you have a closeup of the headstock and a picture of the back?
As for what to do with it, I'm in a similar situation with a mauled SB-1000 I picked up in Japan:
In my case I decided to go for the Cliff Burton treatment! I just dropped it off to a luthier in Korea and it's going to be re-fretted (neck was warped when I got it), have those P/J holes filled in, and then refinished all black. I will post a thread later as I get updates.
If you are good at DIY then I would try to fix it up how you like, but the condition of my 1000 is way beyond me so I just look at it as buying a "new bass"! It's still going to be a lot cheaper than an SB Re-Issue and especially the Cliff Burton tribute model.
As for a pickup, you can always get an Aria pickup replacement. I've heard this guy makes very good ones: http://www.rautiaguitars.net/aria-pro-ii.html
Also Reed James makes a replacement (sorry don't have the link offhand but you can Google it).